Image caption
Businessman Neil Heywood died on 15 November in the Chinese city of Chongqing

China has promised a thorough investigation into a top politician linked to the death of a UK man.

In an editorial, state-run agency Xinhua said the probe into Bo Xilai and his wife over the death of Neil Heywood showed the Communist Party's commitment to the rule of law.

The editorial came a day after Britain's prime minister raised the case with a visiting Chinese official.

It is one of several such pieces in state media in recent days.

Mr Heywood died on 15 November 2011 in the city of Chongqing, where Bo Xilai used to be the party chief.

Mr Bo, now sacked from the post, is now being investigated for "serious discipline violations" and his wife Gu Kailai for "suspicion of homicide".

'Not above the law'

The Xinhua editorial said the party had made "a resolute decision to thoroughly investigate related events and release information in a timely manner".

The move showed its "determination to safeguard the socialist rule of law, to investigate and handle every discipline violation and never tolerate corruption".

"The investigation into Bo... serves as a declaration to all party members that no matter what position one holds, party members shall never place themselves over party discipline and the law," it concluded.

In recent days, a series of articles casting the downfall of Bo Xilai as a simple case of legal wrong doing have appeared in state media, reports the BBC's Martin Patience.

TIMELINE: BO XILAI SCANDAL

2 Feb: Chongqing police chief Wang Lijun is demoted, confirming he has fallen out with the city's Communist Party boss, Bo Xilai.

6 Feb: Mr Wang flees to the US consulate in nearby Chengdu, where he spends the night. Many believe he went there to seek asylum.

5 Mar: China announces that Bo Xilai has been removed from his post in Chongqing.

20 Mar: Rumours suggest that Mr Bo could be linked to the death of British businessman Neil Heywood, who died in Chongqing last November.

10 Apr: China says Bo Xilai has been suspended from party posts and his wife is being investigated over My Heywood's death.

But the scandal - China's biggest in years - comes ahead of a leadership change in Beijing due to get under way in October.

Some suspect that the party are using legal procedures as a pretext for a purge, our correspondent says.

In political cases - such as this one - it is the Communist Party and not the courts that makes the decisions, our correspondent adds.

Britain, meanwhile, has called on China to carry out a full investigation free of interference.

Prime Minister David Cameron raised the case with Chinese politburo member Li Changchun on Tuesday when they met at Downing Street, offering "any necessary assistance" to help China investigate the death.